Sulfuric acid flue gas combination valve and use method thereof

Abstract

The sulfuric acid flue gas combination valve comprises a valve body, a valve plate, shaft sleeves and a valve rod, the shaft sleeves are installed in installation holes in the two ends of the valve body, the valve body comprises a first valve body and a second valve body, and the first valve body and the second valve body are folded to contain the valve plate and the valve rod inside. Flange faces are arranged on the matching faces of the first valve body and the second valve body respectively, the flange faces are detachably connected and folded through bolts, two sections of hoops are arranged outside the flange faces, and the two sections of hoops symmetrically surround the peripheral faces of the flange faces and are connected into a whole through bolts. The valve has the beneficial effects that a first valve body and second valve body combined type assembly process is adopted, a hoop structure is additionally arranged in the middle of the valve body formed by folding the first valve body and the second valve body, a telescopic function is added to the single side of the valve body, and due to the structural design, the valve body can be easily dismantled during maintenance and repair, so that the maintenance cost is reduced, and the maintenance efficiency is improved. And the on-site rapid online cleaning and overhauling time is greatly shortened.

Description

Technical Field

[0001] The invention relates to the field of sulfuric acid production, and in particular to a sulfuric acid fume combination valve and a use method thereof. Background Art

[0002] The butterfly valve is a simple regulating valve. The design features of the butterfly valve include good wear resistance, stable and reliable operation, convenient operation, and sensitive action, making it an ideal choice for handling dusty gas and flue gas pipelines. It is widely used in ventilation and dust removal systems, especially in dusty gas, ventilation purification equipment, sulfuric acid flue gas pipelines, etc., as a flow control and throttling device. This application of butterfly valves is not limited to the cut-off type, that is, used to block or cut off the airflow in the pipeline, but also includes the regulating type, that is, it plays a role in balancing the flow in the ventilation system.

[0003] The flue gas duct contains dust and acid mud. The temperature of conventional butterfly valves drops after stopping, and the acid mud easily accumulates and hardens on the valve stem sleeve. At the same time, the metal profile has a cold shrinkage coefficient. When the working temperature changes, it is easy to cause the gap between the metals to narrow, and the valve stem and the sleeve to bite each other, and the valve cannot be opened and closed. In addition, because there is too much dust in the flue gas duct, it will accumulate on the valve body sealing surface and exceed the height of the valve body sealing surface, hindering the valve plate from opening and closing. The valve needs to be dismantled, resulting in the inability to quickly clean and repair on site, seriously affecting production.

[0004] For example, Chinese utility model patent publication number CN221943208U discloses a corrosion-resistant and wear-resistant butterfly valve, including a valve body, a valve stem and a valve plate. The valve body includes a base layer, a wear-resistant layer and a reinforcement layer. Heat transfer holes are provided on both side surfaces of the valve stem, a heating rod is installed inside the valve stem, a connecting hole is provided on the side surface of half of the valve plate, and a heating chamber is provided inside the valve plate. This patent can effectively increase the wear resistance and corrosion resistance of the entire valve body by spraying the wear-resistant layer on the outer surface of the base layer, and slowly increase the temperature inside the heating chamber through the heating rod. Its valve body is an integrated structure, and does not involve the problem of acid mud accumulating and hardening on the valve stem sleeve, and the valve shaft and sleeve biting each other when the working temperature changes and cannot be quickly repaired.

[0005] Another example is China Utility Model Patent Publication No. CN222351589U, which discloses a butterfly valve with a heating structure, including a butterfly valve body, a heating component installed on the butterfly valve body, and a protective shell, on which a primary motor is installed. The output end of the primary motor is connected to a screw rod, and the end of the screw rod away from the primary motor is rotatably connected to the butterfly valve body through a bearing, and the screw rod is threadedly connected to a movable mounting seat, and the movable mounting seat is arranged in the protective shell, and a heating plate is installed on the movable mounting seat, and the heating plate extends into the butterfly valve body, and the heating plate extends into the inner cavity of the valve body, and can contact with the fluid to reduce the loss in the heat transfer process. The butterfly valve of this patent is an integrated structure, and cannot be quickly repaired when it needs to be disassembled.

[0006] China Utility Model Patent Publication No. CN208565581U discloses a butterfly valve for preventing valve stem from getting stuck, including a valve body, a valve stem, a butterfly plate, a bracket and a transmission device. An axial hole is correspondingly provided on the upper and lower parts of the valve body. The valve stem passes through the axial hole and is fixedly connected to the butterfly plate by a cylindrical pin. Disc springs are sleeved at the upper and lower ends of the valve stem in the gap between the butterfly plate and the valve body. An upper sleeve and a lower sleeve are respectively provided at both ends of the valve stem at the axial hole position of the valve body. The valve stem is filled with packing in the gap between the upper sleeve and the axial hole. A pressure plate is sleeved on the valve stem above the packing. The top of the valve stem is fixedly connected to the transmission device. The patent sleeves disc springs at the upper and lower ends of the valve stem in the gap between the butterfly plate and the valve body to prevent dust and particles from entering between the valve stem and the axial hole. However, the disc spring is located in the valve body. Firstly, it is easy to hinder the operation of the valve plate. Secondly, dust will accumulate on the disc spring, hindering the valve plate from switching. Summary of the invention

[0007] The technical problem to be solved by the present invention is that the existing butterfly valve body is an integrated structure, and cannot be quickly disassembled for maintenance when the valve stem encounters a problem. The cooperation between the valve stem and the shaft sleeve is likely to cause at least one of them to be stuck in the flue gas duct. Therefore, a sulfuric acid flue gas combination valve and a method of using the same are provided.

[0008] The technical solution of the present invention is: a sulfuric acid fume combination valve, comprising: a valve body, a valve plate, a shaft sleeve and a valve stem, the shaft sleeve is installed in the mounting holes at both ends of the valve body, the valve body comprises a first valve body and a second valve body, the first valve body and the second valve body are closed to accommodate the valve plate and the valve stem, the mating surfaces of the first valve body and the second valve body are respectively provided with flange surfaces, the flange surfaces are detachably connected and closed by bolts, and two sections of clamps are provided outside the flange surfaces, the two sections of clamps are symmetrically surrounded by the circumference of the flange surface and are connected as a whole by bolts.

[0009] The improvement of the above scheme is that an installation space is reserved at one end of the installation hole close to the valve plate, and one end of the valve stem is provided with a boss located in the installation space, and the end of the boss close to the valve plate is connected to a metal bellows that sleeves the valve stem, and the end of the metal bellows is connected to a retaining ring that slides with the valve stem, and the retaining ring is made of a polymer material.

[0010] In the above solution, the retaining ring is in an arc shape that bends toward the valve plate.

[0011] The boss in the above solution includes a base and a thickened portion, the base is made of the same material as the valve stem, and the thickened portion is made of a polymer material.

[0012] In the above solution, the boss is in the shape of an arc that bends away from the valve plate.

[0013] In the above solution, the boss is made of polymer material, and is in an arc shape that bends away from the valve plate.

[0014] A further improvement of the above solution is that temperature control mechanisms are respectively installed at both ends of the valve stem outside the valve body.

[0015] A further improvement of the above solution is that an expansion joint is installed on the outer end surface of the first valve body.

[0016] In the above solution, the sealing surface of the valve plate and the sealing surface of the valve body are complementary spherical sections.

[0017] A method for using a sulfuric acid fume combination valve comprises the following steps: connecting the sulfuric acid fume combination valve in a fume duct, the metal bellows being heated and expanded and elongated in a high-temperature fume environment, pushing the retaining ring to move toward a valve plate, and at the same time, the retaining ring being heated and expanded and having an interference fit with an installation space, preventing smoke and dust from entering the installation space; when the sulfuric acid fume combination valve stops working, the metal bellows and the retaining ring are cooled and contracted, and the metal bellows radially expands to fit closely with the installation space, preventing dust from entering a shaft sleeve, and providing a heat-insulating space for the shaft sleeve.

[0018] The beneficial effect of the present invention is that it adopts a combined assembly process of the first valve body and the second valve body, and a clamp structure is added to the middle of the valve body formed by the first valve body and the second valve body. The telescopic function is added on one side of the valve body. The design of this structure makes it easy to remove the valve body during maintenance and overhaul, which greatly shortens the time for on-site rapid online cleaning and overhaul. Through this design, the switching function of the valve can be quickly restored to ensure the efficient operation and convenience of maintenance of the equipment; through the cooperation of the boss, the metal bellows and the retaining ring, smoke and dust can be prevented from entering the installation space when the valve body is working, the shaft sleeve is protected, and an isolated insulation space is provided to reduce the possibility of the medium condensing into acid mud and invading the valve stem shaft sleeve, causing the shaft sleeve and the valve stem to bite each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the explosion of the sulfuric acid fume combination valve of the present invention; Figure 2 yes Figure 1 Schematic diagram of the middle boss, metal bellows and retaining ring; Figure 3 It is a schematic diagram of a boss and a retaining ring of a preferred example of the present invention; Figure 4 It is a cross-sectional view of the sulfuric acid fume combination valve of the present invention after removing the boss, the metal bellows and the retaining ring; Figure 5 It is a schematic diagram of the sulfuric acid fume combination valve of the present invention; In the figure, 1. valve body, 11. first valve body, 12. second valve body, 13. flange surface, 14. clamp, 2. valve plate, 3. shaft sleeve, 4. valve stem, 5. mounting hole, 6. boss, 61. base, 62. thickened part, 7. metal bellows, 8. retaining ring, 9. temperature control mechanism, 10. expansion joint. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention are described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0021] like Figure 1 , Figure 5 As shown, a sulfuric acid fume combination valve comprises: a valve body 1, a valve plate 2, a sleeve 3 and a valve stem 4, the sleeve is installed in the mounting holes 5 at both ends of the valve body, the valve body comprises a first valve body 11 and a second valve body 12, the first valve body and the second valve body have two mounting holes respectively, the first valve body and the second valve body are closed to accommodate the valve plate and the valve stem, the sleeve is installed in the mounting hole and is matched with the valve stem clearance, the first valve body and the second valve body are respectively provided with flange surfaces 13 on the matching surfaces, the flange surfaces are detachably connected and closed by bolts, two sections of clamps 14 are arranged outside the flange surface, the two sections of clamps are symmetrically surrounded on the peripheral surface of the flange surface and are connected as a whole by bolts, the first valve body and the second valve body are fixed in one dimension through the correspondingly connected flange surfaces, and the second dimension is fixed through the cooperation of the two sections of clamps, so as to ensure the stability of the valve body after closing. When disassembly is required, it is only necessary to release the clamp and the bolts corresponding to the flange surface to separate the two sections of clamps, and the outer end surface of the first valve body is installed with a telescopic joint 10. By pushing the telescopic joint, the valve body can be easily opened in half. This design greatly simplifies the quick cleaning and inspection process of internal parts, thus significantly improving the efficiency of maintenance. In this way, maintenance personnel can complete the inspection and maintenance work inside the valve body in a shorter time, ensuring the normal operation of the equipment and extending its service life.

[0022] like Figure 1-Figure 4As shown, as a preferred example of the present invention, an installation space is reserved at one end of the installation hole close to the valve plate, and one end of the valve stem is provided with a boss 6 located in the installation space, and the end of the boss close to the valve plate is connected to a metal bellows 7 in which the valve stem is sleeved, and the end of the metal bellows is connected to a retaining ring 8 that slides with the valve stem, and the retaining ring is a polymer material. Specifically, the retaining ring can be polytetrafluoroethylene or polyetheretherketone, which has a large thermal expansion coefficient and can produce obvious expansion when heated. At the same time, it also has good high temperature resistance and corrosion resistance. The boss, the metal bellows and the retaining ring constitute a protective structure, which can prevent the medium from entering the sleeve after condensation and causing the sleeve and the valve stem to be stuck, and can also prevent the temperature change from causing the valve stem and the sleeve to be stuck. The protective structure relatively isolates the internal temperature of the valve body from the temperature of the sleeve area. The protective structure is located in the installation space and will not hinder the normal operation of the valve plate.

[0023] like Figure 3 As shown, the retaining ring is in an arc shape bent toward the valve plate. In this way, when the valve body is working, the high temperature brought by the high-temperature flue gas causes the retaining ring to expand due to heat, and the deformation direction tends to the shaft sleeve, so that it fits tightly with the installation space or even has an interference fit, isolating the medium in the valve body from flowing in.

[0024] As a preferred example of the present invention, the boss includes a base 61 and a thickened portion 62. The base is made of the same material as the valve stem, and the thickened portion is a polymer material, such as polytetrafluoroethylene or polyetheretherketone. The thickened portion will expand thermally in a high-temperature flue gas environment and cooperate with the retaining ring to isolate the sleeve from the valve body. The boss is in an arc shape that bends away from the valve plate and expands toward the valve plate when expanding. The boss can also be made of a polymer material as a whole.

[0025] As a preferred example of the present invention, the two ends of the valve stem outside the valve body are respectively equipped with temperature control mechanisms, which can be a temperature control system based on a thermocouple and a PID controller, a temperature control system based on a thermal resistor and an intelligent temperature controller, or a temperature control system based on an infrared temperature sensor and a PLC, which are all existing technologies and will not be described here. The valve temperature is monitored in real time, and the heating device is automatically adjusted to ensure that the valve can operate stably in any working environment, prevent the sleeve and the valve stem from biting each other, and prevent acid mud from invading the valve stem sleeve and solidifying.

[0026] The sealing surface of the valve plate and the sealing surface of the valve body are complementary spherical sections, so that the sealing surface of the sulfuric acid flue gas combination valve can automatically calibrate the center of the sphere and automatically compensate for wear over travel to ensure sealing performance. At the moment of switching, the sealing surface does not produce friction. When opening, the projected section of the valve plate continuously shrinks and retreats, and retreats faster than shrinking at the beginning of opening. The selection of different types of materials can cope with various working media, with good sealing performance and long sealing life. The volume and weight are much smaller than the ball valve, and the cost is reduced. The switching torque is much lower than the butterfly valve. Meet the zero leakage standard.

[0027] Each component of the present invention, including the valve stem, valve plate and sealing surface, can be disassembled and replaced separately, thus avoiding the high cost and complexity of replacing the entire valve, and saving maintenance time and economic costs.

[0028] A method for using a sulfuric acid flue gas combination valve includes the following steps: connecting the sulfuric acid flue gas combination valve to a flue gas pipeline, the metal bellows expands and stretches due to heat in a high-temperature flue gas environment, pushing the retaining ring to move toward the valve plate, and the retaining ring expands due to heat and has an interference fit with the installation space to prevent smoke and dust from entering the installation space. When the sulfuric acid flue gas combination valve stops working, the metal bellows and the retaining ring cool and shrink, and the shrinkage of the retaining ring may produce a gap with the installation space, and the radial expansion of the metal bellows to fit closely with the installation space can prevent dust from entering the sleeve from the gap, and provide insulation space for the sleeve. Therefore, whether it is in a high-temperature working environment of high-temperature flue gas or a low-temperature environment after shutdown, whether the retaining ring and the metal bellows are in a contracted state or an expanded state, the protective structure always maintains isolation between the inside of the valve body and the sleeve.

Claims

1. A sulfuric acid fume combination valve, comprising: A valve body (1), a valve plate (2), a shaft sleeve (3) and a valve stem (4), characterized in that: the shaft sleeve is installed in the installation holes (5) at both ends of the valve body, the valve body comprises a first valve body (11) and a second valve body (12), the first valve body and the second valve body are closed to accommodate the valve plate and the valve stem, the mating surfaces of the first valve body and the second valve body are respectively provided with flange surfaces (13), the flange surfaces are detachably connected and closed by bolts, and two sections of clamps (14) are provided outside the flange surfaces, the two sections of clamps symmetrically surround the circumference of the flange surfaces and are connected as a whole by bolts.

2. A sulfuric acid fume combination valve as claimed in claim 1, characterized in that: An installation space is reserved at one end of the installation hole close to the valve plate, and a boss (6) located in the installation space is provided at one end of the valve stem. A metal bellows (7) is connected to the end of the boss close to the valve plate, in which the valve stem is sleeved. A retaining ring (8) is connected to the end of the metal bellows to slide with the valve stem, and the retaining ring is made of a polymer material.

3. A sulfuric acid fume combination valve as claimed in claim 2, characterized in that: The retaining ring is in an arc shape bent toward the valve plate.

4. A sulfuric acid fume combination valve as claimed in claim 2, characterized in that: The boss comprises a base (61) and a thickened portion (62); the base is made of the same material as the valve stem, and the thickened portion is made of a polymer material.

5. A sulfuric acid fume combination valve as claimed in claim 4, characterized in that: The boss is in an arc shape that bends away from the valve plate.

6. A sulfuric acid fume combination valve as claimed in claim 2, characterized in that: The boss is made of polymer material and is in an arc shape that bends away from the valve plate.

7. The sulfuric acid fume combination valve according to claim 1, characterized in that: Temperature control mechanisms (9) are respectively installed at two ends of the valve stem located outside the valve body.

8. The sulfuric acid fume combination valve according to claim 1, characterized in that: An expansion joint (10) is installed on the outer end surface of the first valve body.

9. The sulfuric acid fume combination valve according to claim 1, characterized in that: The sealing surface of the valve plate and the sealing surface of the valve body are complementary spherical sections.

10. A method for using a sulfuric acid fume combination valve according to any one of claims 2 to 6, characterized in that: The method comprises the following steps: a sulfuric acid flue gas combination valve is connected to the flue gas pipeline; the metal bellows is heated and expanded and elongated in a high-temperature flue gas environment, pushing the retaining ring to move toward the valve plate; at the same time, the retaining ring is heated and expanded and has an interference fit with the installation space, preventing smoke and dust from entering the installation space; when the sulfuric acid flue gas combination valve stops working, the metal bellows and the retaining ring cool and shrink, and the radial expansion of the metal bellows is to fit closely with the installation space, preventing dust from entering the shaft sleeve and providing a heat-insulating space for the shaft sleeve.

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